Slot machine

ABSTRACT

A slot machine includes a symbol display device, a symbol controller, a game start device, a first lottery device, a game controller, and a switch device. When the game start device receives a signal indicative of an instruction for starting a game from a player, the first lottery device executes a lottery so as to determine the symbols to be displayed in the symbol display device. The game controller executes the game. When the symbols are displayed statically, the switch device receives a signal indicative of a selection of symbols to be replaced with a wild symbol. When the second lottery device determines activation of the switch device, the game controller replaces the symbols with the wild symbol to determine an award.

This application is based on and claims the benefit of priority from Japanese Patent Application No. 2006-140866, filed on 19 May 2006, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a slot machine. More particularly, it relates to a slot machine which provides a player with a chance to select a reel at rest, for which symbols are replaced with a wild symbol when all the reels come to rest.

2. Related Art

There has long been a demand to design a slot machine that not only allows a player to find a game of amusement to be more enjoyable, but also increases a player's expectation of the outcome of a game. For example, Patent Document No. 1 discloses a slot machine which is designed in an effort to meet this demand.

When a game is initiated, the slot machine disclosed in Patent Document No. 1 carries out a variable display mode in which the slot machine continuously replaces plural symbols resting in plural displaying areas with various symbols including a wild symbol. Also the slot machine carries out a resting display mode in which the slot machine controls the varying symbols to come to rest again and displays them in the respective displaying areas. In this way, the slot machine visually displays combinations of symbols which are entitled to plural awards sharing at least one wild symbol or pay lines associated with these combinations.

Patent Document No. 1: Japanese Unexamined Patent Application Publication No. 2004-173950

However, the slot machine described above, which is successful to some extent in allowing players not only to find the game attractive but also to have higher expectations, automatically selects the symbols to be replaced with wild symbols independently of the player. Because the slot machine does not sufficiently encourage the player to participate aggressively in a game or provide chances to feel involved in the development of the game, the slot machine is not successful in motivating the player to be absorbed in enjoying the game. Therefore, it must be concluded that the slot machine can be improved so as to be more attractive and provide higher expectations to players.

SUMMARY OF THE INVENTION

The invention provides a slot machine which is able to allow a player not only to find a game attractive but also to have higher expectations.

The present inventor has conceived the idea that if a player is given a chance to select a column of symbols to be replaced with a wild symbol, the player is not only encouraged to partake enthusiastically in a game, but is also given a chance to feel more involved in the development of the game. In this way, the player is motivated to be absorbed in enjoying the game. A description is given in the following of the invention resulting from this idea.

In an aspect of the invention, a slot machine includes a symbol display device, a symbol controller, a game start device, a first lottery device, a game controller, and a switch device. The symbol display device displays a plurality of symbols. The symbol controller controls the symbol display device to display the symbols. When the game start device receives a signal indicative of an instruction for starting a game from a player, the first lottery device executes a lottery so as to determine symbols to be displayed in the symbol display device. The game controller executes the game. When the symbols are displayed statically, the switch device receives a signal indicative of a selection of symbols to be replaced with a wild symbol. When the second lottery device determines the switch device to be activated, the game controller replaces the selected symbols with the wild symbol to determine an award.

The switch device of the slot machine described above is able to receive the signal indicative of a selection of symbols to be replaced with the wild symbol, when the symbols are displayed statically. As a result, the game controller is able to replace the symbols with the wild symbol to determine an award.

Since the selected symbols are replaced with the wild symbol, a final combination of symbols entitled to an award depends on the selection. Accordingly, although the slot machine automatically determines whether or not the player wins an award, the slot machine of this invention allows the player to feel that he or she has participated in the outcome of a game. In this way, this invention enables the slot machine not only to be more attractive but also to increase the expectations of the player.

In another aspect of the invention, the second lottery device determines the activation of the switch device only when the switch device receives the signal within a predetermined time limit after the symbols are displayed statically.

The symbol display device of the slot machine described above is able to display the wild symbol only if the switch device receives the signal indicative of a selection within the predetermined time limit.

In this way, the slot machine does not display the wild symbol when a player fails to select the symbols to be replaced with the wild symbol within the predetermined time limit. Accordingly, it is anticipated that the player will try to concentrate on a better selection within the time limit while paying attention to the effect caused by the replacement with the wild symbol. As a result, it may be possible for the slot machine to be more attractive and increase the expectations of the player.

In this connection, a player encounters a game in which the player can not expect an increase in game currency whichever symbol display device the player selects, which is to be replaced with the wild symbol. This means that the game does not require replacement of the symbols with the wild symbol. Because whether or not the player selects the symbols does not affect the resulting number of game currency, the player may enjoy a game in different manners. For example, the player may not only try to select a better selection to gain a larger payout, but may consider reserving a selection. This will add another aspect of attractiveness to the game, which may lead the player to be absorbed in the game.

In still another aspect of the invention, a slot machine includes a symbol display device, a symbol controller, a game start device, a first lottery device, a third lottery device, a game controller, a display window, an image display device, a device for activating a touch mode for the image display device, and a symbol replacement device. The symbol display device displays a plurality of symbols. The symbol controller controls the symbol display device to display the symbols. When the game start device receives a signal indicative of an instruction for starting a game from a player, the first lottery device executes a lottery so as to determine symbols to be displayed in the symbol display device. The third lottery device executes a lottery so as to determine whether or not a game proceeds with a high probability mode that allows the player to have a chance to win a bonus award with a high probability. The game controller executes the game. The image display device is disposed so as to cover the display window. The device for activating a touch mode for the image display device receives a signal indicative of an instruction for using a predetermined area of the image display device as a touch switch that receives an action for a selection of symbols to be replaced with a wild symbol. When the action for a selection via the touch switch is accepted, the symbol replacement device displays the wild symbol overlapping with a display area in the display window for the selected symbols such that the symbols are visually replaced with the wild symbol on the image display device. The game controller replaces the selected symbols with the wild symbol to determine an award.

The switch device of the slot machine described above is able to receive the signal indicative of a selection of symbols to be replaced with the wild symbol, when the symbol display device displays the symbols statically. As a result, the game controller is able to replace the selected symbols with the wild symbol to determine an award.

Because the symbols selected by a player are replaced with the wild symbol, a final combination of symbols entitled to an award depends on the selection. Accordingly, although the slot machine automatically determines whether or not a player wins an award, the slot machine of this invention allows the player to feel that he or she has participated in the outcome of a game. In this way, this invention enables the slot machine not only to be more attractive but also to increase the expectations of the player.

In yet another aspect of the invention, the slot machine further includes a second lottery device. The second lottery device executes a lottery so as to determine whether or not to activate the touch mode.

The slot machine described above is able to determine whether or not the selection of symbols to be replaced with the wild card is accepted when the game start device receives the signal.

The first lottery device temporarily determines whether or not a player wins an award for each game in advance. On the other hand, the third lottery device executes the lottery that finalizes the outcome of the game by determining whether or not the player is given a chance to select symbols to be replaced with the wild symbol. In this way, it is possible for the slot machine to be more attractive and give expectations to the player for each game.

In a further aspect of the invention, the slot machine is provided in which, until the symbol display device displays the symbols statically, the image display device displays an image of rendered effects so as to inform the player of a chance to select the symbols to be replaced with the wild symbol via the touch switch. When the image display device activated in the touch mode accepts the selection by the player, the image display device displays an image of a character on the display area.

The slot machine described above is able to allow a player to know whether or not he or she has the chance for a selection, until the symbols are displayed statically. In addition, the appearance of the character subsequent to the selection informs the player that the selection has come into effect.

As a result, the slot machine not only notifies the player of the chance in a visual and direct manner, but may also give a chance for the player to enjoy the rendered effects with interest and expectation.

In a still further aspect of the invention, the slot machine is provided in which, only when the device for activating a touch mode for the image display device receives the signal indicative of the selection within a predetermined time limit after the symbol display device displays the symbols statically, the symbol replacement device replaces the selected symbols with the wild symbol.

The image display device of the slot machine described above is able to display the wild symbol only if the device for activating a touch mode for the image display device receives the signal indicative of a selection within the predetermined time limit.

In this way, the slot machine does not display the wild symbol when a player fails to select the symbols to be replaced with the wild symbol within the predetermined time limit. Accordingly, it is anticipated that the player will try to concentrate on a better selection within the time limit while paying attention to the effect caused by the replacement with the wild symbol. As a result, it may be possible for the slot machine to be more attractive and to increase the expectation of the player.

In this connection, a player encounters a game in which the player can not expect an increase in game currency whichever symbols the player selects, which are to be replaced with the wild symbol. This means that the game does not require replacement of symbols with the wild symbol. Because whether or not the player selects the symbols does not affect the resulting amount of game currency, the player can enjoy the game in different manners. For example, the player may not only try to select a better selection to get a larger payout, but may also consider reserving a selection. This will add another aspect of attractiveness to the game, which may lead the player to be absorbed in the game.

The slot machine according to the invention allows a player to select the symbols to be replaced with the wild symbol, after the symbol display device has come to rest. Accordingly, the slot machine is able to let the player find a game more attractive and have higher expectations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an external appearance of a slot machine according to an embodiment of the invention;

FIG. 2 is an enlarged front view illustrating a display area of the slot machine;

FIG. 3 is a sectional view taken along line A-A of FIG. 2;

FIG. 4 is a perspective view showing an outline for a liquid crystal display of the slot machine as viewed from the rear;

FIG. 5 is an exploded perspective view showing a portion of the liquid crystal display in FIG. 4;

FIG. 6 is a schematic diagram illustrating columns of symbols on circumferential surfaces of mechanical reels;

FIG. 7 is a block diagram showing a controller of the slot machine;

FIG. 8 is a block diagram showing a display/input controller of the slot machine;

FIG. 9 is a flow chart showing a flow of processes for a basic game of the slot machine;

FIG. 10 is a flow chart showing a flow of processes for a basic game of the slot machine;

FIG. 11 is a table showing a probability for winning an award in a lottery of a basic game;

FIG. 12 is a table showing an allocation of symbols;

FIG. 13 is a schematic diagram illustrating a display informing a player of starting the replacement of symbols with a wild symbol;

FIG. 14 is a schematic diagram illustrating a display inviting a player to select a reel;

FIG. 15 is a schematic diagram illustrating a display with a character making an appearance;

FIG. 16 is a schematic view illustrating a display with a wild symbol;

FIG. 17 is a schematic view illustrating a display indicating the awards won by a player; and

FIG. 18 is a table showing the amount of paid out game currency for a basic game.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the invention is now described with reference to the drawings.

As shown in FIG. 1, a slot machine 10 according to the embodiment includes a cabinet 12 and a main door 42.

The cabinet 12, which has a surface accessible by a player, is installed at a certain place of a casino. In the cabinet 12 there are various components, such as a controller 100 (see FIG. 7) and a hopper 44 (see FIG. 7). The controller 100 electrically controls the slot machine 10. The hopper 44 controls the insertion, storage and payout of coins (game currency).

The main door 42 covers the cabinet 12 so that the inside of the cabinet 12 is not seen from outside. The main door 42 is attached to a left side of the cabinet 12 about an axis as seen from front, so that the door 42 swings about the axis in the forward and backward directions and settles in one of selectable open and closed positions. A liquid crystal display 30 is disposed substantially in the center of the main door 42.

The liquid crystal display 30 displays various images associated with a game, including images of rendered effects and those for conveying information. A player proceeds with a game while looking at the various images displayed on the liquid crystal display 30. The liquid crystal display 30 has a transparent liquid crystal panel 34 (see FIG. 4 and FIG. 5). The liquid crystal panel 34 can be selectively switched between transparent and nontransparent modes for its partial or whole screen, and can also display various images. The liquid crystal display 30 will be described in more detail later.

Five mechanical reels 3A, 3B, 3C, 3D and 3E (see FIG. 2 and FIG. 3), each bearing a plurality of symbols on a circumferential surface, are rotatively disposed in a row on a rear side of the liquid crystal display 30. The mechanical reels 3A to 3E and stepper motors 45A, 45B, 45C, 45D and 45E (see FIG. 7) correspond to a symbol display device and a symbol controller, respectively. Plural kinds of symbols for a basic game including a bonus trigger symbol are drawn on a circumferential surface of each mechanical reel. When the transparent liquid crystal panel 34 is in a transparent mode, it is possible to see the symbols of the mechanical reels 3A to 3E.

A substantially flat operation panel 21 is disposed under the liquid crystal display 30. A coin insertion slot 22 for inserting coins into the slot machine 10 is disposed on the right side of the operation panel 21. On its left side are disposed a BET switch 23 and a spin repeat bet switch 24. A player uses the BET switch 23 to determine pay lines that the player desires to make effective out of nine pay lines L1, L2, L3, L4, L5, L6, L7, L8 and L9 (to be described later), and to select the number of coins bet on the pay lines which have been made effective (hereinafter referred to as “effective lines”). The player uses the spin repeat bet switch 24 so as to keep the number of bet coins for a subsequent game. In summary, the player pushes the BET switch 23 and the spin repeat bet switch 24 so as to determine the number of coins bet on the effective lines.

A start switch 25 is disposed on a left side of the BET switch 23 on the operation panel 21. At the start of each basic game the player uses the start switch 25. Pushing one of the start switch 25 and the spin repeat bet switch 24 triggers the start of game, starting the five mechanical reels 3A to 3E rotating.

A payout switch 26 is disposed adjacent to the BET switch 23 on the operation panel 21. When a player pushes the payout switch 26, coins in the slot machine 10 are paid out through a coin payout opening 27 into a coin tray 28. Sound outlets 29, through which effect sounds generated by speakers 41 (see FIG. 7) are conveyed to the outside of the cabinet 12, are disposed at both the right and left sides of the coin payout opening 27 over the coin tray 28.

As shown in FIG. 2, the liquid crystal display 30 includes a front panel 31 and a transparent liquid crystal panel 34 (see FIG. 4 and FIG. 5) on a rear side of the front panel 31. The front panel 31 includes a transparent display surface 31 a and a pattern area 31 b on which patterns are drawn. It is possible to see image information, which is displayed on the transparent liquid crystal panel 34 disposed behind the front panel 31, through the display surface 31 a of the front panel 31. On the other hand, when the transparent liquid crystal panel 34, which covers the front of the mechanical reels 3A to 3E, is in a transparent mode, it is possible to see symbols of the respective mechanical reels 3A to 3E through the display surface 31 a.

Various displays such as a payout number display 18, a credit number display 19 and a BET number display 20 are disposed on the rear and left side of the liquid crystal display 30. In this connection, the pattern area 31 b has transparent areas opposing to the various displays 18 to 20 so that contents they display are visible.

The slot machine 10 has nine pay lines L1 to L9. Each of these pay lines L1 to L9 passes through one symbol for each of the mechanical reels 3A to 3E, when they all come to rest.

Specifically, the first pay line L1 runs so that it passes through an upper symbol of the first mechanical reel 3A, a middle symbol of the second mechanical reel 3B, a lower symbol of the third mechanical reel 3C, a middle symbol of the fourth mechanical reel 3D, and an upper symbol of the fifth mechanical reel 3E.

The second pay line L2 runs so that it passes through upper symbols of the first mechanical reel 3A and the second mechanical reel 3B, a middle symbol of the third mechanical reel 3C, and lower symbols of the fourth mechanical reel 3D and the fifth mechanical reel 3E.

The third pay line L3 runs horizontally straight so that it passes through the upper symbols of the first to fifth mechanical reels 3A to 3E.

The fourth pay line L4 runs so that it passes through a middle symbol of the first mechanical reel 3A, a lower symbol of the second mechanical reel 3B, a middle symbol of the third mechanical reel 3C, an upper symbol of the fourth mechanical reel 3D, and a middle symbol of the fifth mechanical reel 3E.

The fifth pay line L5 runs horizontally straight so that it passes through the middle symbols of the first to fifth mechanical reels 3A to 3E.

The sixth pay line L6 runs so that it passes through a middle symbol of the first mechanical reel 3A, an upper symbol of the second mechanical reel 3B, a middle symbol of the third mechanical reel 3C, a lower symbol of the fourth mechanical reel 3D, and a middle symbol of the fifth mechanical reel 3E.

The seventh pay line L7 runs horizontally straight so that it passes through the lower symbols of the first to fifth mechanical reels 3A to 3E.

The eighth pay line L8 runs so that it passes through lower symbols of the first mechanical reel 3A and the second mechanical reel 3B, a middle symbol of the third mechanical reel 3C, and upper symbols of the fourth mechanical reel 3D and the fifth mechanical reel 3E.

The ninth pay line L9 runs so that it passes through a lower symbol of the first mechanical reel 3A, a middle symbol of the second mechanical reel 3B, an upper symbol of the third mechanical reel 3C, a middle symbol of the fourth mechanical reel 3D, and a lower symbol of the fifth mechanical reel 3E.

If a player pushes the BET switch 23 once, the third pay line L3, the fifth pay line L5 and the seventh pay line L7 are made effective, for example. At the same time, the slot machine 10 collects one coin as a credit medal.

If a player pushes the BET switch 23 twice, the first pay line L1, the fourth pay line L4 and the eighth pay line L8 are made effective, for example, in addition to the above-mentioned three pay lines. At the same time, the slot machine 10 collects two coins as credit medals.

If the player pushes the BET switch three times, the second pay line L2, the sixth pay line L6 and the ninth pay line L9 are made effective in addition to the above-mentioned six pay lines. At the same time, the slot machine 10 collects three coins as credit medals.

The payout number display 18 displays the number of coins to be paid out when a player wins an award. The credit number display 19 displays the number of coins stored in the slot machine 10 as credit. The BET number display 20 displays a BET number, which represents the number of coins bet on the effective lines described above. The displays 18 to 20 each include a seven-segment display. Alternatively, the liquid crystal display 30 can also display images on the transparent liquid crystal panel 34 in place of the displays 18 to 20.

As shown in FIG. 3, each of the mechanical reels 3A to 3E is individually rotatively supported by a reel frame 54. Though not shown, stepper motors 45A to 45E (to be described later) which rotate and stop the mechanical reels 3A to 3E are attached to the reel frame 54. The reel frame 54 is disposed between an upper frame 52 and a lower frame 53 which are attached to a main frame 55.

As shown in FIG. 4 and FIG. 5, the liquid crystal display 30 displays images associated with a basic game and a free game. The liquid crystal display 30 includes a front panel 31 having a touch panel 32 and a display panel 33, a transparent liquid crystal panel 34, a light guiding panel 35, a reflective film 36, fluorescent lamps 37 a, 37 b, 38 a and 38 b, lamp holders 39 a, 39 b, 39 c, 39 d, 39 e, 39 f, 39 g and 39 h, and a table carrier package (TCP), on which an IC for driving the transparent liquid crystal panel 34 is mounted. It is noted that although not shown in FIG. 4 and FIG. 5, it may be possible for the TCP to include a flexible printed board (not shown) connected with terminals of the transparent liquid crystal panel 34.

Straddling the mechanical reels 3A to 3E, the liquid crystal display 30 is disposed in front of the display areas of the mechanical reels 3A to 3E (in front of the display surface 31 a). Each of the mechanical reels 3A to 3E and the liquid crystal display 30 are spaced a predetermined distance apart.

The touch panel 32 is made of a transparent material. The display panel 33 is also made of a transparent material. Patterns and the like are laid out on the display panel 33 so as not to interfere with the various displays 18 to 20. In other words, the display panel 33 has a first area with the patterns and the like, which corresponds to the pattern area 31 b of the front panel 31, and a second area without them corresponding to the display surface 31 a (see FIG. 2). It may be alternatively possible to eliminate the pattern area 31 b so that the display surface 31 a occupies the whole surface of the front panel 31. In this case, it may be possible to select one of two approaches: one is to lay out no patterns on the display panel 33, and the other one is to eliminate the display panel 33.

It should be noted that electric circuits and the like which are disposed behind the display panel 33 to drive the various displays 18 to 20 are not shown in FIG. 4 or FIG. 5.

The transparent liquid crystal panel 34 includes a first transparent substrate such as a sheet of glass having a layer of thin film transistor, and a second transparent substrate opposing to the first substrate. A liquid crystal is encapsulated in the gap between the first and second substrates. A normally white mode is selected for the transparent liquid crystal panel 34 as a display mode. A normally white mode provides white display, in which light penetrating to the displaying side of the liquid crystal panel 34 is visible from outside, while the liquid crystal is not driven. The use of a liquid crystal panel 34 with a normally white mode allows a player to see the symbols of the respective mechanical reels 3A to 3E in variable and resting modes in the case that the liquid crystal fails to be driven. Accordingly, this enables the player to continue enjoying a game in such an occasion. In other words, it is possible for the player to enjoy a game with the variable and resting displays of the respective mechanical reels 3A to 3E even if the failure described above occurs.

The light guiding plate 35 guides light coming from the fluorescent lamps 37 a and 37 b to the transparent liquid crystal panel 34, in other words, it illuminates the transparent liquid crystal panel 34. The light guiding plate 35 is disposed behind the transparent liquid crystal panel 34, and made of a transparent material, which allows light to pass through, such as a plate of acrylic resin having a thickness of 2 cm.

The reflective film 36, which is made of a silver-deposited white polyester film or a silver-deposited aluminum film, for example, reflects light introduced into the light guiding plate 35 towards the front of the light guiding plate 35. The reflective film 36 includes a reflective area 36A and a nonreflective area (light permeable area) 36B. The nonreflective area 36B made of a transparent material lies in an area of the front panel 31 which covers the front of the mechanical reels 3A to 3E.

The fluorescent lamps 37 a and 37 b are disposed along an upper end portion and a lower end portion of the light guiding plate 35, respectively. Both ends of respective lamps 37 a and 37 b are supported by a pair of lamp holders 39 a and 39 b and a pair of lamp holders 39 g and 39 h. The light cast by the fluorescent lamps 37 a and 37 b is reflected off the reflective area 36A of the reflective film 36 to illuminate the transparent liquid crystal panel 34. On the other hand, the fluorescent lamps 38 a and 38 b are disposed behind the reflective film 36 at an upper portion and a lower portion, respectively, so as to face the mechanical reels 3A to 3E. Both ends of respective lamps 38 a and 38 b are supported by a pair of lamp holders 39 c and 39 d and a pair of lamp holders 39 e and 39 f. The light cast by the fluorescent lamps 38 a and 38 b is reflected off the surfaces of the mechanical reels 3A to 3E to travel into the nonreflective area 36B, illuminating the transparent liquid panel 34. As described above, in the liquid crystal display 30, the light from the fluorescent lamps 37 a and 37 b as well as 38 a and 38 b simultaneously illuminates the transparent liquid crystal panel 34. In this way, one area of the liquid crystal display 30 corresponding to the nonreflective area 36B of the reflective film 36 has selectable transparent and nontransparent modes according to whether or not the liquid crystal is driven. In contrast, the other area of the liquid crystal display 30 corresponding to the reflective area 36A has only a nontransparent mode, regardless of whether the liquid crystal is driven.

Although the slot machine 10 described above has a partial portion of the display area of the liquid crystal display 30 for which transparent and nontransparent modes are selectively applicable, it may be alternatively possible to apply these modes to the whole portion. In order to implement this alternative case, it may be possible to adopt a reflective film 36 whose whole area is a nonreflective area 36B, or to eliminate the reflective film 36.

FIG. 6 shows a column of twenty-one symbols for each of the mechanical reels 3A to 3E. As shown in FIG. 6, code numbers “00” to “20” are assigned to symbols for each of the mechanical reels 3A to 3E. These code numbers are tabulated as a data table which is stored (memorized) in ROM 108 (see FIG. 7) to be described later. Each of the mechanical reels 3A to 3E bears a column of symbols including: a “bonus” trigger symbol (symbol 61), and hereinafter referred to as “bonus”; a “wild” symbol (symbol 62), “wild”; a “treasure box” symbol (symbol 63), “treasure box”; a “gold mask” symbol (symbol 64), “gold mask”; a “holy grail” symbol (symbol 65), “holy grail”; a “compass and map” symbol (symbol 66), “compass and map”; a “snake” symbol (symbol 67), “snake”; an “ace” symbol (symbol 68), “ace”; a “king” symbol (symbol 69), “king”; a “queen” symbol (symbol 70), “queen”; a “jack” symbol (symbol 71), “jack”; and a “10” symbol (symbol 72), “10”. When each of the mechanical reels 3A to 3E is rotated in the normal direction, a column of symbols moves in a direction shown by an arrow in FIG. 6 (from up to down).

In the embodiment, roles including “bonus”, “wild”, “snake”, “treasure box”, “gold mask”, “holy grail”, “compass and map”, “ace”, “king”, “queen”, “jack”, and “10” are provided to form an award. Award data is control information which correlates a profit (the number of payout coins) given to a player and a combination of symbols for an award. The control information is applied to stop control for each of the mechanical reels 3A to 3E, switching of games, and payout of coins.

The slot machine 10 of the embodiment is able to provide a basic game to align symbols along a pay line, and a free game different from the basic game.

As shown in FIG. 7, the controller 100 is a micro computer, which includes interface circuits 102, an input/output bus 104, CPU 106, ROM 108, RAM 110, a communication interface circuit 111, a random number generator 112, a motor drive circuit 120, a speaker drive circuit 122, a hopper drive circuit 124, a display drive circuit 128 and a display/input controller 200.

The interface circuits 102 are electrically connected with the input/output bus 104, which carries out input and output of data signals and address signals for CPU 106.

The start switch 25 is electrically connected with the interface circuits 102. In the interface circuits 102, a start signal generated by the start switch 25 is transformed into a predetermined form of signal to be supplied to the input/output bus 104.

The BET switch 23, the spin repeat bet switch 24 and the payout switch 26 are also electrically connected with the interface circuits 102. In the interface circuits 102, a switching signal generated by each of these switches 23, 24 and 25 is transformed into a predetermined form of signal to be supplied to the input/output bus 104.

A coin sensor 43 is also electrically connected with the interface circuits 102. The coin sensor 43 detects coins inserted into the coin insertion slot 22, and is disposed at an appropriate position relative to the coin insertion slot 22. In the interface circuits 102, a sensing signal generated by the coin sensor 43 is transformed into a predetermined form of signal to be supplied to the input/output bus 104.

A circuit 46 for detecting a reel position is also electrically connected with the interface circuits 102. The circuit 46 detects a rotational position of each of the mechanical reels 3A to 3E receiving pulse signals sent by a sensor for detecting a reel rotational position (not shown). In the interface circuits 102, a signal generated by the circuit 46 is transformed into a predetermined form of signal to be supplied to the input/output bus 104.

ROM 108 and RAM 110 are also electrically connected with the input/output bus 104.

CPU 106 serves as a first game controller. When the start switch 25 accepts an instruction for starting a basic game, CPU 106 reads out a first game program so as to carry out a basic game. The first game program controls a game in the following manner. The first game program gives an instruction for activating each of the stepper motors 45A to 45E so as to rotate each of the mechanical reels 3A to 3E, initiating a variable display for each of them. Subsequently, the first game program gives an instruction for stopping each of the stepper motors 45A to 45E so as to make each of the mechanical reels 3A to 3E come to rest, providing a resting display for each of them. Giving an instruction for rotating and making the mechanical reels 3A to 3E come to rest again, the first game program gives an instruction for paying out a certain number of coins depending on the award, when the combination of symbols at rest is entitled to an award.

In addition, CPU 106 serves as a second game controller. When a bonus trigger symbol or a combination including a bonus trigger symbol appears while each of the mechanical reels 3A to 3E comes to rest, CPU 106 reads out a second game program so as to start a free game. The second game program is programmed to give an instruction for causing a character to appear and act in a predetermined manner. A description on the action performed by the character in a free game will be given in detail later.

ROM 108 stores a control program to centrally control the slot machine 10, a computer program to carry out routines shown in FIG. 9 and FIG. 10 (hereinafter referred to as “routine program”), initial data to execute the control program, and various data tables for a lottery. In this connection, the routine program includes the first game program, the second game program and the like. The tables shown in FIG. 11, FIG. 12 and FIG. 18 are examples of the data tables described above.

FIG. 11 shows a probability table for a basic game. The table registers a range of random numbers and a probability which are correlated with each award. When random numbers in a range of “0” to “299” out of “0” to “65535” are, for example, extracted in a lottery process of a basic game to be described later, the slot machine 10 determines to generate a bonus as an outcome. In other words, the probability for a combination of symbols at rest to be entitled to a bonus is equal to “300/65536”. On the other hand, when random numbers in a range of “10000” to “65535” out of “0” to “65535” are extracted, the slot machine 10 determines to generate a blank. In other words, the probability for a combination of symbols at rest to be a blank is equal to “55536/65536”.

FIG. 12 shows a symbol allocation table. The table registers code numbers that are correlated with positions of respective symbols in the column of each of the mechanical reels 3A to 3E. In other words, the table has information on the symbols on the circumferential surface of each of the mechanical reels 3A to 3E in a form of the code numbers.

FIG. 18 shows a payout table for an award of a basic game. The table registers the correlated number of coins paid out for an award, depending on the number of coins bet on a game as credit. When “wild” appears at a time of determining an award, for example, the slot machine 10 pays out fifty coins for the BET credit number of “1”, a hundred coins for the BET credit number of “2”, and a hundred and fifty coins for the BET credit number of “3”.

As shown in FIG. 7, RAM 110 temporarily stores flags, variables and the like which are used in the control program described above.

The communication interface circuit 111 is electrically connected with the input/output bus 104. The communication interface circuit 111 is for communication with servers and the like through various communication networks including public telecommunication networks and LAN.

The random number generator 112 is also electrically connected with the input/output bus 104. The random number generator 112 generates random numbers in a predetermined range of “0” to “65535” (the sixteenth power of two minus one), for example. It may be alternatively possible that CPU 106 generates random numbers.

The motor drive circuit 120 and the display drive circuit 128 are electrically connected with the input/output bus 104. The motor drive circuit 120 drives the stepper motors 45A to 45E. The display drive circuit 128 drives the various displays 18 to 20. CPU 116 controls the stepper motors 45A to 45E through the motor drive circuit 120, and the displays 18 to 20 through the display drive circuit 128.

The speaker drive circuit 122 for the speaker 41 is also electrically connected with the input/output bus 104. CPU 106 reads out sound data stored in ROM 108, controlling transmission of the sound data to the speaker drive circuit 122 through the input/output bus 104. In this way, the speaker 41 generates a predetermined effect sound.

The hopper drive circuit 124 for driving the hopper 44 is also electrically connected with the input/output bus 104. When CPU 106 receives a payout signal from the payout switch 26, CPU 106 controls transmission of a drive signal to the hopper drive circuit 124. Accordingly, the hopper 44 pays out coins such that the number of them is equivalent to the current number of coins remaining as credit, which is stored in a predetermined memory area of RAM 110.

The display/input controller 200 is also electrically connected with the input/output bus 104. CPU 106 generates an instruction for displaying an image according to the status and outcome of a game, controlling transmission of the instruction to the display/input controller 200 through the input/output bus 104. When the display/input controller 200 receives the instruction from CPU 106, it generates a drive signal, transmitting it to the liquid crystal display 30. In this way, the liquid crystal display 30 displays an image on its transparent liquid crystal panel 34. Receiving an input signal from the touch panel 32 on the liquid crystal display 30, the display/input controller 200 transmits the input signal to CPU 106 through the input/output bus 104.

As shown in FIG. 8, the aforementioned display/input controller 200 is a sub-microcomputer which controls image displaying processes and input signals coming from the touch panel 32. The controller 200 includes an interface circuit 202, an input/output bus 204, CPU 206, ROM 208, RAM 210, VDP 212, video RAM 214, ROM 216 for image data, a drive circuit 218, and a touch panel control circuit 220.

The interface circuit 202 is electrically connected with the input/output bus 204. An instruction for displaying an image generated by CPU 106 of the controller 100 is given to the input/output bus 204 through the interface circuit 202. The input/output bus 204 conducts input and output of data signals and address signals for CPU 206.

ROM 208 and RAM 210 are also electrically connected with the input/output bus 204. A computer program for controlling display is stored in ROM 208. In response to an instruction for displaying an image sent from CPU 106 of the controller 100, the computer program generates an instruction for generating a drive signal to be supplied to the liquid crystal display 30. On the other hand, RAM 210 stores flags and variables applied to the computer program for controlling display.

VDP 212 is also electrically connected with the input/output bus 204. VDP 212, which includes a so-called sprite circuit, screen circuit and pallet circuit, is a processor which is able to perform versatile processing to display images on the liquid crystal display 30. The video RAM 214 and ROM 106 for image data are electrically connected with VDP 212. The video RAM 214 stores image data in response to an instruction for displaying an image, which is given by CPU 106 of the controller 100. ROM 216 stores various image data including image data of rendered effects. Moreover, the drive circuit 218 that generates drive signals for the liquid crystal display 30 is electrically connected with VDP 212.

CPU 206 reads out the display control program stored in ROM 208 and executes it, controlling the video RAM 214 to store the image data, which is displayed on the liquid crystal display 30 in response to the instruction sent by CPU 106 of the controller 100. This instruction for displaying an image includes various types of instructions, including one for displaying an image of rendered effects described above.

ROM 216 for image data stores various image data including the image data of rendered effects.

The touch panel control circuit 220 receives a signal resulting from an action applied to the touch panel 32 which serves as a touch switch on the liquid crystal display 30. The touch panel control circuit 220 transmits the signal to CPU 106 through the input/output bus 204.

As explained above, it is understood that various processes described in the appended claims are executed by the controller 100, which includes ROM 108, CPU 106, RAM 110 and the display/input controller 200. ROM 108 stores computer programs for executing the routines described above. CPU 106 conducts various kinds of control in accordance with the computer programs stored in ROM 108. RAM 110 serves as a working area for CPU 106. The display/input controller 200 controls driving of the liquid crystal display 30. The processes executed by the display/input controller 200 may be, but are not necessarily, included in the processes described in the appended claims. The display/input controller 200 includes CPU 206, ROM 208, RAM 210, VDP 212, the video RAM 214, ROM 216 for image data, the drive circuit 218, and the touch panel control circuit 220. This will be made more definite by the following description on an operation of the slot machine 10 with reference to FIG. 9 and FIG. 10.

FIG. 9 and FIG. 10 show routines for controlling the slot machine 10 executed by the controller 100. A series of routines in FIG. 9 and FIG. 10 is executed, which are read out at a predetermined timing from the main program executed in advance, of the slot machine 10.

In the following description, the slot machine 10 has been in operation in advance, and variables used by CPU 106 of the controller 100 have been initialized to predetermined values. Accordingly, the slot machine 10 is in normal operation.

A description is first given of a flow for processes in a basic game with reference to FIG. 9 and FIG. 10.

CPU 106 of the controller 100 determines whether or not coins inserted by a player remain as credit (step S1). More specifically, CPU 106 reads out a credit number C stored in RAM 110, executing processes according to the credit number C. When the credit number C equals “0” (NO in step S1), CPU 106 terminates the routine without executing any process, because it is not possible to start a game. When the credit number C is not less than “1” (YES in step S1), CPU 106 determines that coins remain as credit, moving the process to step S2.

In step S2, CPU 106 determines whether or not a pushing action has been applied to the spin bet repeat switch 24. When the switch 24 has been pushed and CPU 106 receives a signal from the switch 24 (YES in step S2), CPU 106 moves the process to step S16. On the other hand, when CPU 106 does not receive a signal from the switch 24 after a predetermined lapse of time (NO in step S2), CPU 106 determines that the switch 24 has not been pushed and moves the process to step S3.

In step S3, CPU 106 determines conditions for a game. More specifically, CPU 106 determines the number of coins bet on pay lines in this game. Receiving signals indicative of pushing action for the BET switch 23, CPU 106 determines a BET number applied to a pay line in accordance with the number of received signals, controlling RAM 110 to store this BET number into a predetermined memory area. CPU 106 reads out the credit number C written in RAM 110, subtracting a total BET number including the above-mentioned BET number from the read-out credit number C. CPU 106 controls RAM 110 to store the resulting value into a predetermined memory area. Subsequently, CPU 106 moves the process to step S4.

In step S4, CPU 106 stands by, monitoring a signal coming from the start switch 25. When CPU 106 receives a signal indicative of pushing action for the start switch 25 (YES in step S4), CPU 106 determines that the start switch 25 has been turned on, moving the process to step S5.

On the other hand, in step S16, CPU 106 determines whether or not the credit number C is equal to or greater than the total bet number in a previous game. In this process, CPU 106 determines whether or not it is possible to start a game so long as the spin repeat bet switch 24 has been turned on. When the spin repeat bet switch 24 is pushed and a signal coming from the switch 24 enters CPU 106, CPU 106 reads out the credit number C and the BET number for the effective pay lines L1 to L9 in the previous game. CPU 106 selects a subsequent process according to whether or not the current credit number C is equal to or greater than the total bet number for the previous game. When CPU 106 determines that the credit number C is less than the total bet number (NO in step S16), CPU 106 terminates the routine without any processes, because it is not possible to start a game. On the other hand, when CPU 106 determines that the credit number C is equal to or greater than the total bet number for the previous game (YES in step S16), CPU 106 subtracts the total bet number for the previous game from the credit number C, controlling RAM 110 to store the resulting value into a predetermined memory area. Subsequently, CPU 106 moves the process to step S5.

In step S5, CPU 106 carries out a basic game lottery process, which determines awards by an electronic lottery in the slot machine 10. A description is given of specifics for the basic game lottery process.

CPU 106 first determines symbols to be displayed for the pay lines. CPU 106 gives an instruction to the random number generator 112 so as to extract random numbers in a predetermined range (“0” to “65535” in this embodiment). CPU 106 controls RAM 110 to store the extracted random numbers into a predetermined memory area. Although the random number generator 112 disposed outside CPU 106 generates the random numbers in this embodiment, it may be alternatively possible for CPU 106 to generate random numbers. Reading out the probability table (see FIG. 11) and a combination table (not shown) for a basic game, CPU 106 controls RAM 110 to store them into a predetermined memory area. In this connection, the probability table for the basic game described above is prepared for each reel. Accessing to RAM 110, CPU 106 reads out the probability table and the combination table, and searches the probability table with the random numbers as parameters so as to determine the symbols to be displayed for the pay lines. After determining an award combination, CPU 106 controls RAM 110 to store it into a predetermined memory area. Reading out the random numbers and data for the award combination from RAM 110, CPU 106 then determines the symbols to be displayed, according to the random numbers and the data. During this process CPU 106 reads out the symbol allocation table (see FIG. 12) stored in ROM 108, and controls RAM 110 to store it into a predetermined memory area. CPU 106 controls RAM 110 to store the data of the symbols to be displayed in a predetermined memory area. It may be alternatively possible to determine symbols to be displayed independently for each reel with the probability table.

Determining the symbols to be displayed for the pay lines described above, CPU 106 determines whether or not the combination of the symbols is entitled to an award. If it is, CPU 106 sets an award flag indicating a type of award so as to generate the award. CPU 106 controls RAM 110 to store the activated award flag into a predetermined memory area. On the other hand, if the combination is a blank, CPU 106 does not set an award flag activated.

In the following step S6, CPU 106 controls the mechanical reels 3A to 3E to start rotating. More specifically, CPU 106 controls the mechanical reels 3A to 3E to start rotating sequentially or simultaneously according to the symbol allocation table stored in RAM 110.

After starting the rotation of the mechanical reels 3A to 3E, CPU 106 counts the number of drive pulses transmitted to each of the stepper motors 45A to 45E, controlling RAM 110 to store it into a predetermined memory area. Reset pulses, which are generated each time the mechanical reels 3A to 3E rotate, enter CPU 106 through the circuit 46 for detecting a reel position. CPU 106 controls RAM 110 to clear the drive pulse numbers to be “0” with a reset pulse. In this way, a count number representative of a rotational position with respect to one rotation for each of the mechanical reels 3A to 3E is stored in a predetermined memory area of RAM 110. The symbol allocation table stored in RAM 110 correlates a rotational position and a symbol for each of the mechanical reels 3A to 3E. When CPU 106 searches the symbol allocation table, CPU 106 correlates one of code numbers given at regular rotational pitches relative to a reference point indicated by a reset pulse and a symbol code number assigned to a symbol for each of the mechanical reels 3A to 3E.

After starting the rotation of the mechanical reels 3A to 3E, CPU 106 controls the liquid crystal display 30 to display an image of airplane 81 on the display surface 31 a (step S7). A process in step S7 allows the liquid crystal display 30 to display an image shown in FIG. 13 on the display surface 31 a.

FIG. 13 illustrates the display surface 31 a on which CPU 106 controls the liquid crystal display 30 to display the image of flying airplane 81 while the mechanical reels 3A to 3E are rotating. While displaying the flying airplane 81, the liquid crystal display 30 informs a player of a chance to replace the symbols of a reel with a wild symbol after the mechanical reels 3A to 3E come to rest. The speaker 41 generates a sound of flying airplane, “boom!!” as an effect sound synchronized with the image of flying airplane 81.

It may be possible to regard “a wild symbol” as “a wild symbol which can be substituted for any symbol” or “a wild symbol which can serve as all the symbols.

In this embodiment of the invention, it may be possible to select either one of the following approaches: one approach is that CPU 106 is so arranged that a player is able to select one reel to be replaced with a wild symbol for each game; and the other one is that CPU 106 is arranged to determine whether or not a player has a chance of replacement by lottery at a start of a game. Furthermore, it may be alternatively possible for CPU 106 to carry out a lottery for each game, at regular intervals, each two games, for example, or at random.

Subsequently, CPU 106 stands by before a predetermined time has elapsed (step S8). When the predetermined time has elapsed (YES in step S8), CPU 106 automatically controls each of the mechanical reels 3A to 3E to come to rest (step S9). More specifically, CPU 106 controls each of the mechanical reels 3A to 3E to come to rest sequentially or simultaneously such that the symbols are displayed statically in accordance with the award combinations stored in RAM 110, which has been determined in step S5.

When all the mechanical reels 3A to 3E have come to rest, CPU 106 controls the liquid crystal display 30 to display an image indicating readiness for receiving reel selection on the display surface 31 a (step S10). This process in step S10 allows the liquid crystal display 30 to display an image shown in FIG. 14 on the display surface 31 a.

FIG. 14 shows the display surface 31 a when CPU 106 is ready for receiving a selection of reel, whose symbols are to be replaced with a wild symbol, after the mechanical reels 3A to 3E come to rest. CPU 106 controls the liquid crystal display 30 to display hand symbols 82A to 82E on the display surface 31 a so that the hand symbols 82A to 82E lie adjacent to statically displayed areas 83A to 83E for the reels. In this way, the display surface 31 a is able to serve as a touch panel 32. When a player touches one of the display areas 83A to 83E, CPU 106 identifies a reel to be replaced with a wild symbol.

Therefore, the player is able to know that the display surface 31 a serves as the touch panel 32 (touch switch) and he or she is able to select one reel to be replaced with a wild symbol by touching one of the statically displayed areas 83A to 83E. When CPU 106 completes the process in step S10, CPU 106 moves the process to step S1.

In step S11, CPU 106 determines whether or not one reel has been selected, receiving a signal coming from the touch panel 32. When the determination is affirmative (YES), CPU 106 moves the process to step S12. When the determination is negative (NO), CPU 106 repeats the process in step S11 until the determination becomes affirmative.

In step S12, CPU 106 controls the liquid crystal display 30 to display an image of a character on the display surface 31 a. This process in step S12 allows the liquid crystal display 30 to display images shown in FIG. 15 and FIG. 16 on the display surface 31 a.

FIG. 15 illustrates the liquid crystal display 30 which displays an image of a character 84 on the statically displayed area 83C when CPU 106 accepts the third reel selected by a player as shown in FIG. 14. CPU 106 controls the liquid crystal display 30 to display the character 84 descending a rope ladder on the display area 83C, allowing the player to know that the selection has been accepted. The speaker 41 generates a sound of the rope ladder, “bassa!!” as an effect sound.

When the character 84 has descended the rope ladder to reach the ground, CPU 106 controls the liquid crystal display 30 to display a wild symbol as shown in FIG. 16.

FIG. 16 illustrates the liquid crystal display 30 which is controlled by CPU 106 to display “Wild” as well as the character 84 on the statically displayed area 83C, when the character 84 has descended the rope ladder to reach the ground as shown in FIG. 15. In this way, a player knows that the whole third reel has been replaced with a wild symbol. The speaker 41 generates a sound for a leading character “jajan!!” as an effect sound. When CPU 106 completes the process in step S12, CPU 106 moves the process to step S13.

In step S13, CPU 106 determines whether or not there is a combination of symbols entitled to an award (step S13). CPU 106 makes the determination based on an award flag for a pay line stored in the predetermined memory area of RAM 110. When an award flag is not activated (NO in step S13), CPU 106 determines there is no combination entitled to an award, terminating the routine. On the other hand, when a flag is activated (YES in step S13), CPU 106 determines there is a combination entitled to an award, moving the process to step S14.

In step S14, CPU 106 determines whether or not the combination entitled to an award is a “bonus”, which gives a player a chance to try a free game. CPU 106 makes the determination based on a type of flag stored in RAM 110. When an activated flag coincides with a “bonus” award (YES in step S14), CPU 106 determines a start of a free game, moving the process to step 15. On the other hand, when the activated flag coincides with an award except for “bonus” (NO in step S14), CPU 106 determines a payout of coins in accordance with the award, moving the process to step S17.

In step S15, CPU 106 controls a process for a free game. When the free game is finished, CPU 106 terminates the routine.

In step S17, CPU 106 controls the liquid crystal display 30 to display an image illustrating pay lines shown in FIG. 17 on the display surface 31 a. Subsequently, CPU 106 moves the process to step S18.

FIG. 17 illustrates the liquid crystal display 30 which is controlled by CPU 106 to display the pay lines, when CPU 106 accepts a selection of the third reel to be replaced with a wild symbol. In this connection, the wild symbol is able to substitute for every symbol. This means that when one more symbol is required to be entitled to an award for a pay line, it is possible to win the award by completing the combination with a wild symbol.

The pay lines L1 to L9 as shown in FIG. 2 are selected for the pay lines described above as an example. When all the symbols of a reel at rest are replaced with a wild symbol, pay lines are not restricted to the pay lines L1 to L9. Accordingly, right, upper right, lower right, left, upper left and lower left symbols as seen from a symbol of a reel, are permitted to be included in a pay line. It should be noted that an upper right symbol represents a symbol lying vertically upward adjacent to a right-side symbol, which is horizontally adjacent to a particular symbol. Other lower right, upper left and lower left symbols lie in a similar manner as described above.

As a result, pay lines shown in FIG. 17 are established. The speaker 41 generates voice of the leading character, “Yeh!!”, to be synchronized with the image indicating the pay lines.

Since a player is able to select a reel for which the symbols are to be replaced with a wild symbol, the resulting award varies depending on the selected reel. As the player tries to win an award with a larger amount of game currency, the player is given a chance to enjoy a game with more excitement and expectations.

It may be alternatively possible for CPU 106 to reject the replacement of symbols with a wild symbol, unless CPU 106 receives a selection of a reel from a player within a time limit.

In this way, the player tries to concentrate his or her attention on the selection of a reel within the time limit, seeking for an award, which provides as much game currency as possible. Therefore, the player plays the game with more excitement and expectations.

A player encounters a game, in which the player can not get more game currency whichever reel to be replaced with a wild symbol the player selects. This means that the game does not require the replacement of symbols with a wild symbol. Because whether or not the player selects a reel for which the symbols are replaced with a wild symbol within the time limit does not affect the resulting amount of game currency, the player enjoys the game, considering the reservation of a selection, in addition to finding a better selection to get a bigger payout. This will add another aspect of attractiveness to the game.

In step S18, CPU 106 controls a payout of coins according to an award except for “bonus”. More specifically, CPU 106 searches the payout table for an award of a basic game (see FIG. 18), calculating the number of coins to be paid out for the award. CPU 106 reads out the credit number C stored in RAM 110. Adding the number of coins to the credit number C, CPU 106 controls RAM 110 to store the resulting summation in a predetermined memory area. CPU 106 controls the credit number display 19 to display the stored number. When CPU 106 completes the process in step S18, CPU 106 terminates the routine.

This embodiment of the invention will achieve the following advantages.

The slot machine 10 includes a symbol display device (the mechanical reels 3A to 3E, for example), an image display device (the liquid crystal display 30), a device for selecting a touch mode for the image display device (the touch panel 32), a symbol replacement device (the resting display areas 83A to 83E), and a game controller (CPU 106). When the symbol display device comes to rest, the device for selecting a touch mode allows a predetermined area of the image display device to serve as a touch switch, which receives a selection of a reel from a player, for which the symbols are to be replaced with a wild symbol. The symbol replacement device displays a wild symbol, which overlaps with a display area for the selected reel in a display window. Accordingly, the symbols on the selected reel are visually replaced with the wild symbol. The game controller determines an award, taking into account the wild symbol replacing the symbols on the selected reel.

Since the symbols on one symbol display device which is selected by a player are replaced with a wild symbol, the final combinations of symbols entitled to awards depend on the selection. Accordingly, even if the slot machine of this invention once automatically determines whether or not a player wins an award, it allows the player to feel that he or she has participated in the outcome of the game. In this way, the invention provides a slot machine 10 that is not only more attractive but also successful in increasing the expectations of a player.

It is understood that the invention is not limited to the embodiment described above.

In the embodiment described above, the game controller (CPU 106) determines an award, considering the replacement of symbols on the reel with a wild symbol to be valid only for a particular game. However, the invention is not limited to such a method. For example, it may be alternatively possible to leave the wild symbol on the reel valid for another round of game, when the wild symbol does not bring about an award for the particular game (in a case of blank).

This method may give a player interest and the expectation that a subsequent game has a better chance to win an award, even if the current game with the wild symbol results in a blank.

In the embodiment described above, all symbols on a reel selected by a player are replaced with a wild symbol. However, this invention is not limited to this method. For example, it may be alternatively possible to replace a symbol on a reel with a wild symbol for a plurality of reels.

Although it is not necessary to specify the number of symbols to be replaced with wild symbols, it may be preferable that the number does not exceed three. The reason for this is that when a reel comes to rest, the number of symbols displayed on the reel is three, which is the maximum number of symbols to be replaced. Moreover, it may be preferable that the allowable number of symbols to be replaced for a pay line be restricted to be one. This prevents a player from wining an award on any occasion by replacing plural symbols with wild symbols for the pay line.

Since a player has more variations for selection of symbols to be replaced with wild symbols, the player may concentrate on a game so as to get more game currency. In this way, the player may enjoy a game with more excitement and expectation.

In the embodiment described above, CPU 106 automatically controls a plurality of reels to come to rest in a predetermined sequence. This invention is not limited to this method. For example, it may be alternatively possible to adopt a plurality of stop buttons each for stopping a reel of the slot machine 10. CPU 106 controls the reels to come to rest in accordance with a sequence of pushing actions applied to the stop buttons by a player.

CPU 106 gives an instruction for stopping a reel in response to the action applied by the player. Accordingly, the player may concentrate on the action for the stop buttons so as to get more game currency. This may allow the player to enjoy a game with more interest and expectations.

In the embodiment described above, the invention has been described with a mechanical slot machine as an example. In addition to the mechanical slot machine, it is possible to apply this invention to a so-called simulated reel slot machine. This means that the invention has no restriction for how variable and static displays are implemented.

In the embodiment described above, this invention is applied to a slot machine (so-called casino machine) having no button for stopping reels, which automatically come to rest. It is also possible to apply this invention to a slot machine (so-called pach-slot machine) in which reels come to rest in accordance with a sequence of pushing actions applied to stop buttons by a player. This means that this invention has no restriction for how static display is implemented.

It will be apparent to one skilled in the art that various changes and modifications can be made without departing from the amended claims.

It will now be appreciated from the foregoing description that the invention is not limited to the particularly illustrated embodiment discussed above. Also, it is to be understood that the advantages described in the embodiment of the invention are exemplary of the best advantages resulting from the invention, and the advantages according to the invention are not limited to those described in the embodiment of the invention. 

1. A slot machine comprising: a symbol display device for displaying a plurality of symbols; a symbol controller for controlling the symbol display device to display the symbols; a game start device; a first lottery device for executing a lottery so as to determine symbols to be displayed in the symbol display device when the game start device receives a signal indicative of an instruction for starting a game from a player; a game controller for executing the game; a switch device for receiving a signal indicative of a selection of symbols to be replaced with a wild symbol when the symbols are displayed statically; and a second lottery device for executing a lottery so as to determine whether or not the switch device is activated, wherein when the second lottery device determines the switch device to be activated, the game controller replaces the selected symbols with the wild symbol to determine an award.
 2. A slot machine according to claim 1, wherein the second lottery device determines the activation of the switch device only when the switch device receives the signal within a predetermined time limit after the symbols are displayed statically.
 3. A slot machine according to claim 1, wherein the selected symbols to be replaced with the wild symbol are on one column of the symbol display device.
 4. A slot machine according to claim 1, wherein the selected symbols to be replaced with the wild symbol are on a plurality of columns of the symbol display device.
 5. A slot machine according to claim 1, wherein the symbol controller controls the symbols to be displayed statically in a predetermined sequence.
 6. A slot machine according to claim 1 further comprising stop buttons, wherein the symbol controller controls the symbols to be displayed statically in accordance with a sequence of pushing actions applied to the stop buttons.
 7. A slot machine comprising: a symbol display device for displaying a plurality of symbols; a symbol controller for controlling the symbol display device to display the symbols; a game start device; a first lottery device for executing a lottery so as to determine symbols to be displayed in the symbol display device when the game start device receives a signal indicative of an instruction for starting a game from a player; a third lottery device for executing a lottery so as to determine whether or not a game proceeds with a high probability mode that allows the player to have a chance to win a bonus award with a high probability; a game controller for executing the game; a display window; an image display device disposed to cover the display window; a device for activating a touch mode for the image display device; and a symbol replacement device for displaying a wild symbol overlapping with a display area in the display window corresponding to one column of the symbol display device selected by the player via the image display activated in the touch mode, wherein the game controller replaces the selected symbols with the wild symbol to determine an award.
 8. A slot machine according to claim 7 further comprising a second lottery device for executing a lottery so as to determine whether or not the touch mode is activated.
 9. A slot machine according to claim 8, wherein when the second lottery device outputs an activation of the touch mode, the image display device displays an image of a character on the display area.
 10. A slot machine according to claim 7, wherein until the symbol display device displays the symbols statically, the image display device displays an image of rendered effects so as to inform the player of a chance to select the symbols to be replaced with the wild symbol via the image display device.
 11. A slot machine according to claim 7, wherein only when the device for activating a touch mode for the image display device receives the signal indicative of the selection within a predetermined time limit after the symbols are displayed statically, the symbol replacement device replaces the selected symbols with the wild symbol.
 12. A method for controlling a slot machine comprising: (a) displaying a plurality of symbols; (b) receiving a signal indicative of an instruction for a start for each game; (c) executing a first lottery so as to determine symbols to be displayed when reception of the signal in step b is completed; (d) executing the game; (e) receiving a signal indicative of a selection of symbols to be replaced with a wild symbol when the symbols are displayed statically; (f) executing a second lottery so as to determine whether or not to accept the signal received in step (e); and (g) replacing the selected symbols with the wild symbol to determine an award, when the signal is accepted in step (f). 